1. Field of the Invention
The present invention relates to a device and a method for conveying bone-in meat which convey the bone-in meat from an arm part or a thigh part of a livestock carcass while involving posture change from a horizontally placed state to a suspended state, and a deboning system of bone-in meat including the device.
2. Discussion of the Background
A carcass of livestock such as a pig, a cow, or a sheep is served as meat. A deboning method of bone-in meat (hereinafter referred to as a “work”) from an arm part or a thigh part of the livestock carcass roughly has a pre-processing step, an incision making step, and a meat separation step. In the pre-processing step, in the case where the work is the thigh part, a hip bone and the like are removed. In the incision making step, an incision is made along a forearm bone and an upper arm bone of the work in the case where the work is the arm part, and an incision is made along a lower thigh bone and a thigh bone of the work in the case where the work is the thigh part. In the meat separation step, meat is torn from bones of the work.
The present inventors propose a deboning system in which the incision making step and the meat separation step are automatically performed.
For example, in the deboning system disclosed in Japanese Patent Application Laid-open No. 2008-99574 (Patent Document 1), the work in which incision making of the forearm bone is manually performed in the pre-processing step is supplied. The supplied work is suspended from a clamp manually, and is sent to a robot arm which performs the incision making step.
A cutter tool is attached to the robot arm, and the cutter tool executes the incision making with a predetermined course using the robot arm. The length of the work is measured by using a photoelectric sensor in advance and the course of the incision making is determined on the basis of the measurement result. During the incision making step, the work is held by a work holding mechanism while being suspended by the clamp.
In addition, in the meat separation step of the deboning system, the work is lifted while being rotated in a state where a cutter is in contact with the work, and the forearm bone and the upper arm bone are thereby removed the work. The lift amount of the work is also determined on the basis of the measurement result of the length of the work.
Thereafter, a shoulder blade is removed from the work. Specifically, after the work from which the forearm bone and the arm bone have been removed is transferred to a belt conveyor, the work is rested at a predetermined position by a V-shaped guide. Subsequently, incision making is performed along the shoulder blade of the work. After the incision making, the work is conveyed again by the belt conveyor. When the work reached a predetermined conveyance position, the belt conveyor is stopped, and the shoulder blade of the work is chucked and removed by a chuck cutter and a U-shaped cutter.
The deboning system disclosed in WO 2009/139031 A1 (Patent Document 2) includes a placement device which automatically suspends the work on the belt conveyor from the clamp. The placement device has the robot arm having a grip part, and the robot arm carries the work to a clamp stand in a state where the tip protruded part of the work is gripped using the grip part, and suspends the work from the clamp stand.
In addition, the deboning system includes a left/right determination unit which determines whether the work is a left part or a right part. Specifically, the thicknesses of both sides of the work are measured, and it is determined whether the work is the left part or the right part on the basis of the measurement result. The incision making step by the cutter tool is performed on the basis of the determination result of the left/right determination unit. That is, an appropriate cutting operation program is selected on the basis of the determination result, and the robot arm operates on the basis of the cutting operation program such that the cutter tool moves along a predetermined course.
In addition, in the deboning system, the meat separation step is divided into two stages and, in the first stage, meat is torn from the lower thigh bone, i.e., a tibia and a fibula using an interosseous scraper. In the subsequent second stage, meat is torn from the thigh bone using a meat separator. During the meat separation step, the lower thigh bone and the thigh bone are suspended from the clamp while they are coupled to each other.